In a mobile communication system, in addition to macro base stations deployed by operators, another kind of base stations, i.e., femtocell or Home eNodeBs (HNB), also exist, which are called access points (APs). In the present disclosure, they are all called HNBs. Such HNB is characterized in a small coverage range and flexible installment.
Due to the coexistence of macro base stations and HNBs, when an HNB and a macro base station are adjacent to or overlap each other, it is necessary to avoid users that belong to the HNB from accessing the HNB. Accessing the HNB means that idle users are forbidden from residing in the HNB after cell selection and active users are forbidden from handing over to the HNB, and in the meantime, the users that belong to the HNB are allowed to access the HNB.
A cell access control method in the prior art is described as follows.
An idle user equipment (UE) is required to select a cell and then reside in the cell. After that, the UE determines whether the UE is allowed to access the HNB that provides services for the cell by reading a system broadcast message of the cell. If the UE is allowed to access the HNB, the UE then performs cell reselection.
An active UE measures all HNBs around and adjacent to the active UE before handover from a macro base station to an HNB, selects measurement reports of HNBs that allow to be accessed, and reports a measurement result, including surrounding macro base stations and HNBs that allow to be accessed, to a source macro base station. The source macro base station then performs a handover determination.
During implementation of the present disclosure, the inventors find that, in the prior art, an idle UE cannot determine whether the UE is allowed to access a current HNB until the UE resides therein, and as a result, the time of cell reselection is delayed.
Furthermore, an active UE is required to measure all HNBs around and adjacent to the UE. This results in increase of calculation amount and system burden.